1. Field of the Invention
This invention relates generally to local area networks (LANs), and more particularly to a system and method for automatic configuration of a new device on a LAN by secure network transmission of configuration parameters, including a shared network security key.
2. Description of the Related Art
LANs are in widespread use in the home and office and are expanding to include the transfer of audio and video between consumer electronic (CE) devices. These LANs include wireless local area networks (WLANs), perhaps the most common of which is based on the well-known IEEE 802.11 or Wi-Fi standards. Other types of WLANs include ultrawideband (UWB) networks that have a fairly short range but very high throughput, and wireless personal area networks (WPANs), such as ZigBee™ and Bluetooth®. Another type of LAN, one that does not use wireless transmission, is a powerline communications (PLC) network that uses the existing electrical wiring in a home or single building, such as a PLC network based on the HomePlug™ standard.
LANs typically include a device that acts as a network controller to connect the network devices together. The network controller may also act as the network's arbitrator, negotiating when network devices can transmit. In an IEEE 802.11 compliant WLAN, the network controller is called the access point (AP). In a PLC network the network controller is called the central controller. In many LANs, there is a need to set up or configure new devices. For example, in an IEEE 802.11 compliant WLAN the configuration information may include a network name or service set identifier (SSID), a channel number, and an optional shared network security key that need to be set in the new device before it can begin to communicate with existing network devices. Typically this configuration information is entered manually into the new device by the user, such as by use of a keypad. For devices without keypads, such as many CE devices like digital televisions (TVs), the configuration process can be difficult and annoying for the user.
In WLANs there is also a desire for secure communication because the wireless transmissions extend beyond the immediate vicinity of the network devices. In some non-wireless LANs, such as PLC networks, secure communication is also desirable because multiple homes or buildings and multiple-residence buildings such as apartment buildings are usually served from a common transformer so that the physical PLC network extends beyond the boundaries of a single residence. Secure communication is especially important in these types of LANs that have CE devices, such as stereo receivers, digital video recorders (DVRs), digital TVs and audio-video (AV) servers, because copyrighted digital audio and video recordings are transmitted over the network.
Secure communication is typically established in these types of non-secure LANs by the use of a shared network security key that is input to a network device during its setup process and used to encrypt and decrypt the transmissions. The shared network security key is stored in all devices that use the encryption method to communicate over the LAN, including the network controller. For example, in an IEEE 802.11 compliant WLAN, the optional shared network security key is based on either the Wired Equivalent Privacy (WEP) or Wi-Fi Protected Access (WPA) encryption standards. In a PLC network based on the HomePlug standard all new devices are shipped with a common publicly-available password that is used to generate a shared network key, but this results in a LAN with non-secure communication. To achieve a secure PLC network configuration, a unique network password must be selected and entered into each device. However, most users do not configure their devices with these security measures because of the inconvenience in configuring the devices with the security key. The user is required to manually enter complex security keys that typically consist of long strings of meaningless characters into multiple devices. The devices may be from various hardware vendors, each having different configuration steps and user interfaces.
Certain systems are commercially available that attempt to reduce the complexity of the configuration process for new LAN devices, and thus encourage the use of security. For example, IEEE 802.11 compliant devices that incorporate the AirStation OneTouch Secure System (AOSS™) from Buffalo Technology are shipped with a common pre-established WEP key and a special button. Activation of the button on the AP and the button on the new device causes the AP to pseudo-randomly generate a new shared network security key and puts the WLAN into a special low-power transmission mode where the AP and the new device can communicate using the common WEP key. The new shared network security key is then transmitted to the new device in the low-power transmission mode. The new device then uses the new shared network security key to communicate with the AP and receive the configuration information in the normal-power transmission mode. The AOSS requires that new devices be manufactured with the AOSS hardware and software, and installed with the common pre-established WEP key.
A method for setting up a new device on an IEEE 802.11 compliant WLAN using a “learning” type of remote control (RC) having both infrared (IR) transmit and receive capability is described in U.S. Published Patent Application US 2004/0203590 A1. In that method the AP and the new device are also equipped with IR transceivers. The RC is placed near the AP and the AP transmits the network WEP key currently in use to the RC via IR. The RC is then placed near the new device and transmits the WEP key to the new device via IR. Once the new device has the WEP key it can communicate with the AP and receive other setup parameters to authenticate and configure the new device. In this method the WEP key remains stored in the RC and is thus non-secure because the RC is a portable non-network device.
What is needed is a LAN with a simple yet secure setup method for new network devices that allows configuration information, including a shared network security key, to be easily and securely transmitted to a new device.